1. Field of the Invention
The present invention relates generally to the provision of feedthrough penetrations in hermetically sealed vessels and, more particularly, is concerned with a replaceable feedthrough module device and method of replacing and/or changing the same being adapted for use in a spacecraft to permit change-out or repair without significant air loss.
2. Description of the Prior Art
For carrying out materials research and production in space as well as many other applications requiring a space environment, an industrial space facility is being constructed for launch and initial operation in the early 1990's. The facility is designed to be a reusable, remotely controlled, free-flying space vehicle in low earth orbit. The facility will provide a pressurized shirtsleeve environment with sustainable power, cooling, and telemetry capabilities.
Plans are for the facility to remain in orbit for an extended time, for instance, 30 years. If the facility is to have a useful lifetime of 30 years in orbit, then it must be maintainable. Thus, the environment of the facility must be controlled and the facility must be capable of regular servicing while in orbit. Specifically, atmosphere and temperature control are required in the interior of the facility to support certain manufacturing processes or experiments, and for man-tended periodic servicing.
Many spacecraft hull penetrations are necessary for supplying electrical signals and power to the interior and for furnishing fluids used for cooling and atmosphere. The most reliable feedthroughs can probably be mounted individually, directly through the pressurized hull of the facility. However, these could not be easily changed or serviced without a major loss of air from the facility. Less reliable feedthroughs need to be changeable by an astronaut or robot since the facility will not be continually man-tended. Certain removable sealed window or viewport concepts have been proposed heretofore; however, none of these appear to be particularly suited for use as a hull penetration for supplying utility services.
Consequently, a need exists for a different approach to a feedthrough concept which will provide effective access with minimum loss of air.